The rheumatology community has recognized the need for results from clinical and economic evaluations of self-care education for arthritis patients to promote public policy deliberations about appropriate third- party reimbursement or other financing mechanisms. While results of research on clinical efficacy suggest modest, but clinically important, outcomes of arthritic patient education, relatively few studies have focussed on osteoarthritis (OA). No thorough evaluations of economic benefit or cost-effectiveness exist in the literature. The purpose of this study will be to evaluate, relative to attention placebo, the effects of individualized self-care education for patients with OA of the knee on disability, pain, health care utilization and costs, and quality of life. Furthermore, we will interrelate health care utilization, costs, and quality of life measures so as to estimate quality-adjusted life years gained (or saved) by patient education, as well as cost-effectiveness (i.e., cost-utility) of self-care education. Subjects in this study will be 368 patients with either idiopathic or post-traumatic OA of the knee. Subjects will be recruited from major primary care practices of the Indiana University Medical Center and from community physicians. Subjects will be allocated at random to Experimental (E) and Control (C) treatment conditions. At baseline, subjects will receive a history and physical examination, and educational, functional status, pain and quality of life assessments. Subjects also will keep a diary of all out- of-pocket OA expenses. E subjects will receive a course of individualized arthritis self-care instruction from an arthritis nurse educator. C subjects view a general arthritis slide tape presentation. We also will control for printed reference materials and for follow-up contact. Subjects will continue to receive ongoing arthritis care from their primary care physicians. For each subject, subsequent study assessment will occur at four-month intervals for a period of one year (i.e., 4, 8, and 12 months postintervention). All postintervention assessments will be conducted by a "blind" research associate and will include an intercurrent history, and repeat administrations of the functional status, pain, and quality of life measures. Subject diaries will be collected and new diaries for the next four months will be issued (except month 12). During the final (12-month) assessment, the educational diagnostic assessment also will be repeated. Statistical analysis of clinical effects will include group comparisons with respect to disability, pain, and quality of life scales. Health care utilization and related costs also will be compared. Using serial measures of the Quality of Well Being Scale, we will estimate quality-adjusted years of life (well years) accumulated by subjects in Groups E and C. Arthritis- related costs in the two groups will be compared to estimate net economic benefit of self-care education for patients with knee OA. Group costs will be related to corresponding totals of well years to produce estimates of cost-utility.